Method of securing hollow tapering boiler-plugs.



APPLICATION, FILED MAY 27,1918.

Patented. Apr. 29,1919.

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NI IEED @ATE% ATEN OFFIQUE.

FREDERICK E. KEY, OF ST. LOUIS, MISSOURI, ASSIGNOR TO KEY BOILER EQUIPMENT G0,, OF ST. LOUIS, MISSOURI, A. CORPORATION OF MI$SOURL METHOD OF SECURING HOLLOW TAPERING BOILER-PLUGS.

Application filed May 27, 1918.

To all whom it may concern:

Be it known that I, FREDERICK E. KEY, a citizen of the United States of America, a resident of the city of St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Methods of Securing Hollow Tapering Boiler-Plugs, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to improvements in methods of securing hollow tapering boiler plugs, the present invention being an im provement on the method disclosed in Patent No. 1,195,687, issued to me on August 22, 1916.

The main object of the present invention is to provide a simple method whereby in expensive tapered plugs may be very se curely and firmly seated in the plug-receiving openings, so as to positively prevent leakage between the plugs and their seats.

In following the earlier method disclosed by the above mentioned patent, the plugreceiving openings are not tapered and the open outer end portions of the plugs are formed in a peculiar manner tocontact with an expanding device whereby said end portions are materially expanded, or stretched. and forced into engagement with their seats.

In accordance with the present invention.

the plug-receiving openings are preferably tapered to conform approximately to the taper of the plugs, and the tapered faces of the plugs are firmly seated in a peculiar manner, by forcing their tapering faces into engagement with the tapered seats, and at the same time advancing the plugs, without materially expanding the metal. Briefly stated, the preferred method consists in first tapering the plug-receiving opening ,to make it conform approximately to the taper of the hollow plug, then inserting the plug from the inside of the boiler, and placing it in engagement with the tapered seat. The next step consists in exerting outward pressure within the plug soas to force an annular portion thereof into engagement with its tapering seat, and at the same time advancing the plug in. the tapered opening. This tightens the plug,- and positively Specification of Letters Patent.

Patented Apr. 29, 18919.

Serial No. 236,910.

prevent leakage I continue the operation by pressing and smoothing the annular portion of the plug which lies opposite the seat, so as to positively force a continuous circular portion of the plug into firm engagement with its seat.

I preferably use an expanding device to force the tapered plug onto its correspondingly formed seat, and also to advance the plug in the opening, but the expanding de vice does not materially expand or mutilate the plug. It draws the plug into the opening and forces the metal of the plug into engagement with the seat, but this operation is performed after the plug is already in contact with its corresponding seat. As a result a continuous circular portion of the plug is positively forced into very firm contact with its seat, so as to positively prevent leakage around the plug; and since this is accomplished without materially expanding or mutilating the metal, the simple plug can be easily hammered from its tapered seat and it can be reused several times.

Figure I is a vertical section showing a portion of the water leg of a boiler equipped with the tapered plugs.

Fig. II is an end view of one of the plugs.

Fig. III is an enlarged detail view of a portion of the wall of the boiler, showing one of the ordinary hand holes as it appears before being tapered or beveled to receive the plug.

Fig. IV is a view similar to Fig. III, showing the tapered or beveled opening, the tapered plug being shown by dotted lines.

Fig. V illustrates the plug mounted in the opening and an expanding device which may be used to tighten the plug.

The water leg shown in Fig. I has an inner wall 1 to which the tubes 2 are secured. and an, outer wall ,3 provided with hand holes through which thetubes may be inserted. These hand holes are ordinarily closed by more or less complex and expensive devices, but in following the new method they. are closed by hollow tapered plugs A preferably made of sheet metal. Each plug A is closed at its inner end by a bowed wall 4 having, a convex face exposed to the pressure in the boiler, a bowed wall of this kind being: well adapted to resist such pressure.

The outer end oi. each plug is open to receive an expanding device, or the like, as shown in Fig. V.

In the ordinary boilers, the hand holes are usually formed as shown in Fig. III, so the first step of the new method preferably consists in tapering, or beveling, the circular walls of these openings to make them conform at least approximately to the taper of the plugs. Fig. IV shows one of the openings as it appears after the tapering or beveling operation. inserting the plugs from the inside of the boiler, introducing them into the plug-receiving openings and placing them in contact with their seats. If desired the relatively large inner ends of the plugs may be struck by a hammer to force them ontotheir seats. The plug is thus positioned for the next operation, which consists in exerting.

outward pressure within the plug by rolling an annular portion of the inner face of the plug directly opposite the beveled annular seat, and at the same time advancing the tapering plug-in the correspondingly formed opening, so as to tighten the tapering plug on its beveled seat.

To accomplish this I may use an expanding device constructed as shown in Fig. V, wherein 6 designates pressure rolls rotatably mounted in a revolving cage 7, and adapted to be driven through the medium of a rotary pin 8 havinga tapered end 8', which contacts with all of the rollers. The cage 7 is rotatably mounted in a thrust member 9 which engages the boiler wall 3. 10. designates a screw rigidly secured to the cage 7, and 11 is a threaded sleeve fitted to the screw 10 for thepurpose of advancing the tapered pin 8 between the rollers 6. This pin 8 has an annular collar 12 which lies withinthe sleeve 11. A collar 1-3, rigidly se-- cured to the pin 8 by means of a small pin 14, is provided with a clutch pin 15 whereby rotary motion is transmitted from the collar 13 to the threaded sleeve 11.

If the tapered pin 8 is rotated while the parts occupy the positions shown in Fig. V, motion will be transmitted from the collar 13 and through the clutch pin 15 to the threaded sleeve 11, thereby causing said sleeve to rotate on the screw 10 soas to move the pin 8 longitudinally, said pin 8 having a collar 12 which engages a portion of the sleeve 11. The rotary movement .of thecpin 8 causes the rollers 6 to turn on their own axes and to revolve in a circularpath around the axis of-said pin 8, the tapered :end portion 8 of said .pin being in contact with all of the rollers. The longitudinal movement of thelpin 8, due to.theilongitudinal movement of sleeve :11 on the screw 10, causes the tapered end-8 to advance between the rollers 6, thereby forcing; the rollers away from the axis ofpin 8.- It will now be un-- The next step consists in derstood that the expanding device may be actuated to revolve the rollers 6 on the tapering inner face of the cap A, at the same time gradually moving the rollers away from each other to tighten the plug on its seat.

When the desired maximum outward pres sure is transmitted through the pressure rolls 6, the longitudinal movement of the tapered pin 8 should be stopped so as to avoid undue pressure, but the rollers 6 should be permit ted to transmit this maximum pressure uniformly at all points throughout their circular path. To accomplish this I rotate the tapered pin 8 without advancing it longitudinally. The clutch pin is disengaged from the threaded sleeve 11, and the rotary movement of pin 8 is continued without transmitting power from the collar 13 to the threaded sleeve 11. The pressure rollers (3 then travel in a circular path without moving away from each other, and an annular portion of the tapered plugis thus smoothed and firmly :lorced onto its beveled seat.

It is important to note that. the axes of the rollers 6 are not parallel with the axis of pin 8. The center line X of each roller 6 is arranged at an angle to the center line X of pin 8, as suggested by Fig. V, wherein I have exaggerated the inclination of the rollers 6 for the purpose of more clearly illustrating this feature. If the pressure rolls 6 are mounted in this manner they will tend to form spiral paths or tracks on the inner face otthe plug, and they will cause the tapered plug to advance in the-plug-receiving opening during the operationof pressing the plug onto its seat. The plug is therefore pressed outwardly to engage its seat and at the same time drawn into the tapering opening, so that a very firm contact is obtained between the tapered face of the plug and its tapering seat. Actual experience has shown that the desired results can be obtained by mounting the pressure rollers 6 with their axes at an angle of about 3 to the center line of the pin 8.

By inserting the tapered plug from the inside of the boiler I avoid the necessity of using fastening devices to attach the plug. The boiler pressure tends to tighten the plug. Y

The beveled seat conforming to the taper of the plug is very desirable, for it enables the removable plug to be more easily and more firmly seated without n'iutilating or destroying the .metal. In actual practice I have found that the expanding device herein shown can be used to form the beveled seats, and that all of the seats made by this device will conform to a uniform or standard taper, corresponding to the taper of the plugs. In forming the seats, the expanding device is applied to the boiler approximately 'as SllOWl'l in Fig. V, but the pressure rolls 6 are of course arranged in contact with the circular wall of the opening, instead of being in contact with the plug. The tapered pin 8 is rotated and advanced longitudinally for the purpose of spreading the pressure rolls and at the same time rolling them on the seat. Thereafter the clutch pin 15 is detached from the threaded sleeve 11, and the rotary motion of the pin 8 is continued for the purpose of revolving the pressure rolls 6 without spreading them away from each other, thereby smoothing the tapered or beveled seat.

A highly important feature of the method herein disclosed consists in the combination of steps whereby a simple and inexpensive sheet metal plug is manipulated to produce an easily removable closure, at least equal in efficiency to the combination of gaskets, plugs, screws, nuts, etc., ordinarily used to close the hand holes in boilers. This C0111- bination of steps preferably involves the production of a seat conforming approximately to the taper of the plug, inserting the plug from the inside of the boiler to place it in contact with its correspondingly shaped seat, and then producing the necessary continuous circular fluid-tight oint by first pressing the metal of the plug outwardly and into very firm engagement with its seat, at the same time drawing the tapered plug into the tapering opening. This tightens the plug but does not necessarily produce an absolutely leakproof contact between the plu and the boiler. The pressure rolls 6 of the expanding device gradually move away from each other during the preliminary operation of advancing and tightening the plug, and this does not uniformly tighten the plug at all points through its annular seat. I therefore prefer to continue the operation by detaching the clutch pin 15, as previously pointed out, and then rotating the pin 8. An annular portion of the plug is thus smoothed and pressed onto its seat, so as to positively eliminate irregularities which may otherwise be caused by imperfections in the plug or seat.

I claim:

1. The method of securing hollow tapering boiler plugs which comprises beveling a circular plu -receiving opening to make it conform approximately to the taper of the plug, there forminga beveled annular seat for the plug, inserting the hollow tapered plug,,

from the inside of the boiler, into said opening and into engagement with said beveled seat, thereby positioning the plug with its relatively large end inside of the boiler where it will be exposed to the boiler pressure, then exerting outward pressure within the plug by rolling an annular portion of the inner face of the plug directly opposite said beveled annular seat, and at the same time advancing the tapering plug in the correspondingly formed opening, so as to tighten the tapering plug on its beveled seat.

The method of securing hollow tapering boiler plugs which comprises forming an annular seat for the plug, inserting the hollow tapered plug, from the inside of the boiler, into said opening and into engagement with said annular seat, exerting outward pressure within the plug by rolling an annular portion of the inner face of the plug at points directly opposite said annular seat, thereby forcing portions of the metal outwardly and into firm engagement with said annular seat, at the same time advancing the tapering plug in the plug-receiving opening, thereby tightsuing the plug in the opening, and then pressing and smoothing the annular portion of the inner face of the plug which lies opposite said annular seat so as to positively force a continuous circular portion of the plug into firm engagement with said seat.

3. The method of securing hollow plugs which comprises beveling a circular plugreceiving opening to make it conform approximately to the taper of the plug, thereby forming a beveled annular seat for the plug, placing the hollow tapered plug in said opening and into engagement with said beveled annular seat. exerting outward pressure within the plug by rolling an annular portion of the inner face of the plug at points directly opposite said beveled annular seat, thereby forcing portions of the metal outwardly and into firm engagement with said beveled annular seat without materially expanding the metal of the plug, at the same time advancing the tapering plug in the correspondingly formed opening, thereby tightening the plug in the opening, and then pressing and smoothing the annular portion of the inner face of the plug which lies opposite said annular seat so as to positively force a continuous circular portion of the plug into firm engagement with said seat.

4. The method of tightening hollow tapering boiler plugs which comprises exerting outward pressure within the plug by rolling an annular portion of the inner face of the plug, at the same time advancing the tapering plug in the plug receiving opening, thereby tightening the plug in the opening, and then pressing and smoothing the annular portion of the inner face of the plug which lies opposite to the wall of said opening, so as to make the corresponding annular portion of the outer face of the plug conform precisely to the wall of the opening.

In testimony that I claim the foregoing I hereunto afiix my signature.

FREDERICK E. KEY.

Gopies of this patent may be obtained for five cents each, by addressing: the "tlomznissiener m? Patents.- Weshington, $3. 

